5 Answers
5

The second sense of determine is not “to forecast or predict”, but rather to “find out by investigation, reasoning, or calculation”, sense 4 in Merriam-Webster. Merriam-Webster gives other examples of this sense: “<determine the answer to the problem> <determine a position at sea>”.

The second meaning is often used (to the point of overuse) in the natural sciences: "This experiment allows us to determine the charge of the electron." Obviously no experiment will allow the experimenter to dictate the charge of the electron.

I personally would use the word "estimate" instead; scientific measurements are always subject to experimental uncertainty, and trying to measure the electron charge is certainly not an exception to this rule. "Determine" for me seems to be reaching for the certainty which just isn't there.
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user730Aug 24 '10 at 12:57

The weather forecaster can hardly be certain when determining the weather, either. Anyway, "estimate" is used slightly differently in the natural sciences; it means more often than not that the experimenter really has no clue. When a quantity is measured, it is "determined" to be within a certain margin of error from some value.
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ptomatoAug 25 '10 at 9:40

Actually, I think the word determine is being used here in both cases in the sense of "to decide" or "to resolve". The difference is: in the first case, Zeus is deciding what the weather will be (as it is under his direct control), and in the second case, the weatherman is deciding what the weather should be (a prediction).

The second sentence about the forecaster sounds "off" to my ears as well. If you'll excuse my lapsing into jargon for a few moments, nobody considers weather "deterministic". Certainly one can forecast, predict, or even hazard a guess, but certainly not determine something which has a "random" nature.